The spin polarizations of quark, as functions of the magnetic fields \(eB\) ,
for various \(\kappa _{2}\) , are shown in Fig. REF , respectively.
These spin polarizations of \(u/d\)  quark can be obtained from Eq. (REF ).
One can be seen that the spin polarizations are approximately linear for magnetic fields \(eB\) ,
and its absolute magnitude increase with increasing the \(eB\) 
(while vanishes for \(eB\) = 0, as it should).
As \(eB\)  increases, due to the difference between the electric charges, spin polarizations of \(u/d\)  quark
develops a \(\kappa _{2}\) -dependence are shown in the figure.
Comparisons between our results (solid and dot lines) and the TSP with AMM results (hollow points) [1]},
are shown in the figure.
Our results (with \(\kappa _{2}=3.2\) ) are in good agreement with the TSP with AMM results.
Note that \(\langle \bar{q}\sigma ^{12}q\rangle \)  of our results and
the tensor-type spin polarization (TSP) with AMM results (hollow points) [1]}
are positive while is negative in Ref. [3]}.
It can be understood that the definition of spin polarization is along the direction of external magnetic field in this work.
